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Krom J, Meister K, Vilgis TA. Simple Method to Assess Foam Structure and Stability using Hydrophobin and BSA as Model Systems. Chemphyschem 2024; 25:e202400050. [PMID: 38683048 DOI: 10.1002/cphc.202400050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/01/2024]
Abstract
The properties and arrangement of surface-active molecules at air-water interfaces influence foam stability and bubble shape. Such multiscale-relationships necessitate a well-conducted analysis of mesoscopic foam properties. We introduce a novel automated and precise method to characterize bubble growth, size distribution and shape based on image analysis and using the machine learning algorithm Cellpose. Studying the temporal evolution of bubble size and shape facilitates conclusions on foam stability. The addition of two sets of masks, for tiny bubbles and large bubbles, provides for a high precision of analysis. A python script for analysis of the evolution of bubble diameter, circularity and dispersity is provided in the Supporting Information. Using foams stabilized by bovine serum albumin (BSA), hydrophobin (HP), and blends thereof, we show how this technique can be used to precisely characterize foam structures. Foams stabilized by HP show a significantly increased foam stability and rounder bubble shape than BSA-stabilized foams. These differences are induced by the different molecular structure of the two proteins. Our study shows that the proposed method provides an efficient way to analyze relevant foam properties in detail and at low cost, with higher precision than conventional methods of image analysis.
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Affiliation(s)
- Judith Krom
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Konrad Meister
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
- Department of Chemistry and Biochemistry, Boise State University, Boise, Idaho, 83725, United States
| | - Thomas A Vilgis
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
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2
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Interplay between bulk aggregates, surface properties and foam stability of nonionic surfactants. Adv Colloid Interface Sci 2022; 302:102618. [PMID: 35245855 DOI: 10.1016/j.cis.2022.102618] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 02/15/2022] [Accepted: 02/20/2022] [Indexed: 11/21/2022]
Abstract
In our previous study (Mustan et al. 2021) we showed that foams formed from two oil-soluble nonionic surfactants (Span 60 and Brij 72) can remain stable for more than 10 days at room temperature at high sugar concentration. The major aim of the current study is to reveal the interrelation between the surfactant structure and foam stability by investigating 6 polyoxyethelene alkyl ethers and 12 fatty acid esters with a wide variety of hydrophobic chain lengths (C12; C16; C18 and C18:1) and hydrophilic head-groups (sorbitol, glycerol, sucrose). Foams stable for more than 100 days at room temperature are obtained when sucrose palmitate or stearate (P1670 or S1670) are used as surfactants. This exceptional foam stability is related to the gelation of the aqueous phase and to the formation of solid adsorption layer with zero surface tension upon compression, thus preventing water drainage and decelerating the bubble Ostwald ripening. The foam stability decreases with (i) increasing the number of EO groups in polyoxyethylene alkyl ethers and in fatty acid sorbitan esters; (ii) decreasing the number of C-atoms in the surfactant tail for all studied surfactants; (iii) addition of double bond in the surfactant tail. The lower foam stability in all three cases is related to the worse packing of the surfactant molecules within the adsorption layer, leading to faster Ostwald ripening and subsequent bubble coalescence. The diesters present as admixture in the fatty acid esters play an important role in the foam stabilization by further compacting the adsorption layers and lowering the rate of Ostwald ripening. These conclusions can be used as a predictive tool for surfactant selection in the development of food or pharmaceutical foam concentrates that can be diluted before final use.
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3
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Cheng Y, Wang B, Wang Y, Zhang H, Liu C, Yang L, Chen Z, Wang Y, Yang H, Wang Z. Soluble hydrophobin mutants produced in Escherichia coli can self-assemble at various interfaces. J Colloid Interface Sci 2020; 573:384-395. [DOI: 10.1016/j.jcis.2020.04.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 11/30/2022]
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4
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Arjmand S, Tavasoli Z, Ranaei Siadat SO, Saeidi B, Tavana H. Enhancing chimeric hydrophobin II-vascular endothelial growth factor A 165 expression in Pichia pastoris and its efficient purification using hydrophobin counterpart. Int J Biol Macromol 2019; 139:1028-1034. [PMID: 31404600 DOI: 10.1016/j.ijbiomac.2019.08.080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/03/2019] [Accepted: 08/08/2019] [Indexed: 12/18/2022]
Abstract
We report cloning and expressing of recombinant human VEGF-A165, fused at the N-terminal with Hydrophobin II (HFBII) from Trichoderma reseei, in yeast Pichia pastoris. We validated the construct using SDS-PAGE and ELISA against VEGF-A165 and efficiently performed protein purification and enrichment based on HFBII counterpart and using an aqueous two-phase system (ATPS) with nonionic surfactant X-114. We studied the effects of various culture medium additives and interaction effects of positive factors to increase the recombinant HFBII-VEGF-A165 production. Supplementing the Pichia pastoris cell culture medium with Mg2+, Polysorbate 20 (PS 20), and 4-phenylbutyrate (PBA) improved the expression of the chimeric protein. Orthogonal experiments showed that the optimal condition to achieve maximal HFBII-VEGF-A165 production was with the addition of PBA, PS 20, and MgSO4. Under this condition, the production of the target protein was 4.5 times more than that in the medium without the additives. Overall, our approach to produce chimeric HFBII-VEGF-A165 and selectively capture it in ATPS is promising for large-scale protein production without laborious downstream processing.
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Affiliation(s)
- Sareh Arjmand
- Protein Research Center, Shahid Beheshti University, G. C., Tehran, Iran.
| | - Zahra Tavasoli
- Protein Research Center, Shahid Beheshti University, G. C., Tehran, Iran
| | | | - Behanm Saeidi
- Protein Research Center, Shahid Beheshti University, G. C., Tehran, Iran
| | - Hossein Tavana
- Department of Biomedical Engineering, The University of Akron, Akron, OH 44325, USA
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Hähl H, Griffo A, Safaridehkohneh N, Heppe J, Backes S, Lienemann M, Linder MB, Santen L, Laaksonen P, Jacobs K. Dynamic Assembly of Class II Hydrophobins from T. reesei at the Air-Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:9202-9212. [PMID: 31268722 DOI: 10.1021/acs.langmuir.9b01078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Class II hydrophobins are amphiphilic proteins produced by filamentous fungi. One of their typical features is the tendency to accumulate at the interface between an aqueous phase and a hydrophobic phase, such as the air-water interface. The kinetics of the interfacial self-assembly of wild-type hydrophobins HFBI and HFBII and some of their engineered variants at the air-water interface were measured by monitoring the accumulated mass at the interface via nondestructive ellipsometry measurements. The resulting mass vs time curves revealed unusual kinetics for a monolayer formation that did not follow a typical Langmuir-type of behavior but had a rather coverage-independent rate instead. Typically, the full surface coverage was obtained at masses corresponding to a monolayer. The formation of multilayers was not observed. Atomic force microscopy revealed formation and growth of non-fusing protein clusters at the interface. The mechanism of the adsorption was studied by varying the structure or charges of the protein or the ionic strength of the subphase, revealing that the lateral interactions between the hydrophobins play a role in their interfacial assembly. Additionally, a theoretical model was introduced to identify the underlying mechanism of the unconventional adsorption kinetics.
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Affiliation(s)
| | - Alessandra Griffo
- Department of Bioproducts and Biosystems , Aalto University , P.O. Box 16100, FI-00076 Aalto , Finland
| | | | | | - Sebastian Backes
- Federal Institute for Material Research and Testing (BAM) , Unter den Eichen 87 , 12205 Berlin , Germany
| | - Michael Lienemann
- VTT Technical Research Centre of Finland Ltd. , Espoo 02150 , Finland
| | - Markus B Linder
- Department of Bioproducts and Biosystems , Aalto University , P.O. Box 16100, FI-00076 Aalto , Finland
| | | | - Päivi Laaksonen
- Department of Bioproducts and Biosystems , Aalto University , P.O. Box 16100, FI-00076 Aalto , Finland
- HAMK Tech, Häme University of Applied Sciences , P.O. Box 230, Hämeenlinna 13101 , Finland
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6
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Li P, Penfold J, Thomas RK, Xu H. Multilayers formed by polyelectrolyte-surfactant and related mixtures at the air-water interface. Adv Colloid Interface Sci 2019; 269:43-86. [PMID: 31029983 DOI: 10.1016/j.cis.2019.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/13/2019] [Accepted: 04/13/2019] [Indexed: 01/01/2023]
Abstract
The structure and occurrence of multilayered adsorption at the air-water interface of surfactants in combination with other oppositely charged species is reviewed. The main species that trigger multilayer formation are multiply charged metal, oligo- and polyions. The structures vary from the attachment of one or two more or less complete surfactant bilayers to the initial surfactant monolayer at the air-water interface to the attachment of a greater number of bilayers with a more defective structure. The majority of the wide range of observations of such structures have been made using neutron reflectometry. The possible mechanisms for the attraction of surfactant bilayers to an air-water interface are discussed and particular attention is given to the question of whether these structures are true equilibrium structures.
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Affiliation(s)
- Peixun Li
- STFC, Rutherford-Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0RA, United Kingdom
| | - Jeffery Penfold
- STFC, Rutherford-Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0RA, United Kingdom
| | - Robert K Thomas
- Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford, OX1 3QZ, United Kingdom.
| | - Hui Xu
- KLK OLEO, Room 1603, 16th Floor, LZY Tower, 4711 Jiao Tong Road, Putuo District, Shanghai 200331, China
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Fungal Hydrophobins and Their Self-Assembly into Functional Nanomaterials. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1174:161-185. [DOI: 10.1007/978-981-13-9791-2_5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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8
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Xiao Y, Zhang Q, Wang Y, Wang B, Sun F, Han Z, Feng Y, Yang H, Meng S, Wang Z. Dual-functional protein for one-step production of a soluble and targeted fluorescent dye. Theranostics 2018; 8:3111-3125. [PMID: 29896306 PMCID: PMC5996361 DOI: 10.7150/thno.24613] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 03/17/2018] [Indexed: 01/17/2023] Open
Abstract
Low water solubility and poor selectivity are two fundamental limitations that compromise applications of near-infrared (NIR) fluorescent probes. Methods: Here, a simple strategy that can resolve these problems simultaneously was developed by using a novel hybrid protein named RGD-HFBI that is produced by fusion of hydrophobin HFBI and arginine-glycine-aspartic acid (RGD) peptide. This unique hybrid protein inherits self-assembly and targeting functions from HFBI and RGD peptide respectively. Results: Boron-dipyrromethene (BODIPY) used as a model NIR dye can be efficiently dispersed in the RGD-HFBI solution by simple mixing and sonication for 30 min. The data shows that self-assembled RGD-HFBI forms a protein nanocage by using the BODIPY as the assembly template. Cell uptake assay proves that RGD-HFBI/BODIPY can efficiently stain αvβ3 integrin-positive cancer cells. Finally, in vivo affinity tests fully demonstrate that the soluble RGD-HFBI/BODIPY complex selectively targets and labels tumor sites of tumor-bearing mice due to the high selectivity of the RGD peptide. Conclusion: Our one-step strategy using dual-functional RGD-HFBI opens a novel route to generate soluble and targeted NIR fluorescent dyes in a very simple and efficient way and may be developed as a general strategy to broaden their applications.
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Affiliation(s)
- Yunjie Xiao
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Qian Zhang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yanyan Wang
- College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China
| | - Bin Wang
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Fengnan Sun
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Ziyu Han
- College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China
| | - Yaqing Feng
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Haitao Yang
- School of Life Sciences, Tianjin University, Tianjin 300072, China
- Tianjin International Joint Academy of Biotechnology and Medicine, Tianjin 300457, China
| | - Shuxian Meng
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Zefang Wang
- School of Life Sciences, Tianjin University, Tianjin 300072, China
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9
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Zhang X, Kirby SM, Chen Y, Anna SL, Walker LM, Hung FR, Russo PS. Formation and elasticity of membranes of the class II hydrophobin Cerato-ulmin at oil-water interfaces. Colloids Surf B Biointerfaces 2018; 164:98-106. [DOI: 10.1016/j.colsurfb.2018.01.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/29/2017] [Accepted: 01/15/2018] [Indexed: 01/10/2023]
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10
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Virkajärvi V, Sarlin T, Laitila A. Fusarium Profiling and Barley Malt Gushing Propensity. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-2017-3321-01] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Vertti Virkajärvi
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland
| | - Tuija Sarlin
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland
| | - Arja Laitila
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland
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11
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Khalesi M, Deckers S, Riveros-Galan D, Gebruers K, Derdelinckx G. Upgraded Model of Primary Gushing: From Nanobubble Formation until Liquid Expulsion. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-2015-0929-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | | | | | - Kurt Gebruers
- KU Leuven, Department of Microbial and Molecular Systems (M2S), Belgium
| | - Guy Derdelinckx
- KU Leuven, Department of Microbial and Molecular Systems (M2S), Belgium
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Production and characterization of stable foams with fine bubbles from solutions of hydrophobin HFBII and its mixtures with other proteins. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.06.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Aggregation behavior of star-shaped fluoropolymers containing polyhedral oligomeric silsesquioxane (POSS) at the air–water interface. Colloid Polym Sci 2016. [DOI: 10.1007/s00396-016-3986-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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14
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Richter MJ, Schulz A, Subkowski T, Böker A. Adsorption and rheological behavior of an amphiphilic protein at oil/water interfaces. J Colloid Interface Sci 2016; 479:199-206. [DOI: 10.1016/j.jcis.2016.06.062] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 06/24/2016] [Accepted: 06/27/2016] [Indexed: 10/21/2022]
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15
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Khalesi M, Jahanbani R, Riveros-Galan D, Sheikh-Hassani V, Sheikh-Zeinoddin M, Sahihi M, Winterburn J, Derdelinckx G, Moosavi-Movahedi AA. Antioxidant activity and ACE-inhibitory of Class II hydrophobin from wild strain Trichoderma reesei. Int J Biol Macromol 2016; 91:174-9. [DOI: 10.1016/j.ijbiomac.2016.05.068] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/16/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022]
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16
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Danov KD, Stanimirova RD, Kralchevsky PA, Marinova KG, Stoyanov SD, Blijdenstein TB, Cox AR, Pelan EG. Adhesion of bubbles and drops to solid surfaces, and anisotropic surface tensions studied by capillary meniscus dynamometry. Adv Colloid Interface Sci 2016; 233:223-239. [PMID: 26143156 DOI: 10.1016/j.cis.2015.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 06/11/2015] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
Abstract
Here, we review the principle and applications of two recently developed methods: the capillary meniscus dynamometry (CMD) for measuring the surface tension of bubbles/drops, and the capillary bridge dynamometry (CBD) for quantifying the bubble/drop adhesion to solid surfaces. Both methods are based on a new data analysis protocol, which allows one to decouple the two components of non-isotropic surface tension. For an axisymmetric non-fluid interface (e.g. bubble or drop covered by a protein adsorption layer with shear elasticity), the CMD determines the two different components of the anisotropic surface tension, σs and σφ, which are acting along the "meridians" and "parallels", and vary throughout the interface. The method uses data for the instantaneous bubble (drop) profile and capillary pressure, but the procedure for data processing is essentially different from that of the conventional drop shape analysis (DSA) method. In the case of bubble or drop pressed against a substrate, which forms a capillary bridge, the CBD method allows one to determine also the capillary-bridge force for both isotropic (fluid) and anisotropic (solidified) adsorption layers. The experiments on bubble (drop) detachment from the substrate show the existence of a maximal pulling force, Fmax, that can be resisted by an adherent fluid particle. Fmax can be used to quantify the strength of adhesion of bubbles and drops to solid surfaces. Its value is determined by a competition of attractive transversal tension and repulsive disjoining pressure forces. The greatest Fmax values have been measured for bubbles adherent to glass substrates in pea-protein solutions. The bubble/wall adhesion is lower in solutions containing the protein HFBII hydrophobin, which could be explained with the effect of sandwiched protein aggregates. The applicability of the CBD method to emulsion systems is illustrated by experiments with soybean-oil drops adherent to hydrophilic and hydrophobic substrates in egg yolk solutions. The results reveal how the interfacial rigidity, as well as the bubble/wall and drop/wall adhesion forces, can be quantified and controlled in relation to optimizing the properties of foams and emulsions.
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Kirby SM, Zhang X, Russo PS, Anna SL, Walker LM. Formation of a Rigid Hydrophobin Film and Disruption by an Anionic Surfactant at an Air/Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:5542-51. [PMID: 27164189 DOI: 10.1021/acs.langmuir.6b00809] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Hydrophobins are amphiphilic proteins produced by fungi. Cerato-ulmin (CU) is a hydrophobin that has been associated with Dutch elm disease. Like other hydrophobins, CU stabilizes air bubbles and oil droplets through the formation of a persistent protein film at the interface. The behavior of hydrophobins at surfaces has raised interest in their potential applications, including use in surface coatings, food foams, and emulsions and as dispersants. The practical use of hydrophobins requires an improved understanding of the interfacial behavior of these proteins, alone and in the presence of added surfactants. In this study, the adsorption behavior of CU at air/water interfaces is characterized by measuring the surface tension and interfacial rheology as a function of adsorption time. CU is found to adsorb irreversibly at air/water interfaces. The magnitude of the dilatational modulus increases with adsorption time and surface pressure until CU eventually forms a rigid film. The persistence of this film is tested through the sequential addition of strong surfactant sodium dodecyl sulfate (SDS) to the bulk liquid adjacent to the interface. SDS is found to coadsorb to interfaces precoated with a CU film. At high concentrations, the addition of SDS significantly decreases the dilatational modulus, indicating disruption and displacement of CU by SDS. Sequential adsorption results in mixed layers with properties not observed in interfaces generated from complexes formed in the bulk. These results lend insight to the complex interfacial interactions between hydrophobins and surfactants.
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Affiliation(s)
| | - Xujun Zhang
- School of Materials Science and Engineering and School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Paul S Russo
- School of Materials Science and Engineering and School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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18
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Abstract
Fungal hydrophobin is a family of low molecular weight proteins consisting of four disulfide bridges and an extraordinary hydrophobic patch. The hydrophobic patch of hydrophobins and the molecules of gaseous CO2 may interact together and form the stable CO2-nanobubbles covered by an elastic membrane in carbonated beverages. The nanobubbles provide the required energy to provoke primary gushing. Due to the hydrophobicity of hydrophobin, this protein is used as a biosurfactant, foaming agent or encapsulating agent in food products and medicine formulations. Increasing demands for using of hydrophobins led to a challenge regarding production and purification of this product. However, the main issue to use hydrophobin in the industry is the regulatory affairs: yet there is no approved legislation for using hydrophobin in food and beverages. To comply with the legislation, establishing a consistent method for obtaining pure hydrophobins is necessary. Currently, few research teams in Europe are focusing on different aspects of hydrophobins. In this paper, an up-to-date collection of highlights from those special groups about the bio-chemical and physicochemical characteristics of hydrophobins have been studied. The recent advances of those groups concerning the production and purification, positive applications and negative function of hydrophobin are also summarised.
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Xie Y, Chen J, Zhang S, Fan K, Chen G, Zhuang Z, Zeng M, Chen D, Lu L, Yang L, Yang F. The research about microscopic structure of emulsion membrane in O/W emulsion by NMR and its influence to emulsion stability. Int J Pharm 2016; 500:110-9. [PMID: 26784978 DOI: 10.1016/j.ijpharm.2016.01.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 01/02/2016] [Accepted: 01/14/2016] [Indexed: 12/08/2022]
Abstract
PURPOSE This paper discussed the influence of microstructure of emulsion membrane on O/W emulsion stability. METHODS O/W emulsions were emulsified with equal dosage of egg yolk lecithin and increasing dosage of co-emulsifier (oleic acid or HS15). The average particle size and centrifugal stability constant of emulsion, as well as interfacial tension between oil and water phase were determined. The microstructure of emulsion membrane had been studied by (1)H/(13)C NMR, meanwhile the emulsion droplets were visually presented with TEM and IFM. RESULTS With increasing dosage of co-emulsifier, emulsions showed two stable states, under which the signal intensity of characteristic group (orient to lipophilic core) of egg yolk lecithin disappeared in NMR of emulsions, but that (orient to aqueous phase) of co-emulsifiers only had some reduction at the second stable state. At the two stable states, the emulsion membranes were neater in TEM and emulsion droplets were rounder in IFM. Furthermore, the average particle size of emulsions at the second stable state was bigger than that at the first stable state. CONCLUSIONS Egg yolk lecithin and co-emulsifier respectively arranged into monolayer and bilayer emulsion membrane at the two stable states. The microstructure of emulsion membrane was related to the stability of emulsion.
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Affiliation(s)
- Yiqiao Xie
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Jisheng Chen
- Department of Pharmacy, First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Shu Zhang
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Kaiyan Fan
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Gang Chen
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Zerong Zhuang
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Mingying Zeng
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - De Chen
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Longgui Lu
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Linlin Yang
- Guangdong Province Maternity and Child Care Hospital, Guangzhou, Guangdong 510006, China.
| | - Fan Yang
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
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20
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Danov KD, Kralchevsky PA, Radulova GM, Basheva ES, Stoyanov SD, Pelan EG. Shear rheology of mixed protein adsorption layers vs their structure studied by surface force measurements. Adv Colloid Interface Sci 2015; 222:148-61. [PMID: 24828304 DOI: 10.1016/j.cis.2014.04.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 04/20/2014] [Indexed: 11/30/2022]
Abstract
The hydrophobins are proteins that form the most rigid adsorption layers at liquid interfaces in comparison with all other investigated proteins. The mixing of hydrophobin HFBII with other conventional proteins is expected to reduce the surface shear elasticity and viscosity, E(sh) and η(sh), proportional to the fraction of the conventional protein. However, the experiments show that the effect of mixing can be rather different depending on the nature of the additive. If the additive is a globular protein, like β-lactoglobulin and ovalbumin, the surface rigidity is preserved, and even enhanced. The experiments with separate foam films indicate that this is due to the formation of a bilayer structure at the air/water interface. The more hydrophobic HFBII forms the upper layer adjacent to the air phase, whereas the conventional globular protein forms the lower layer that faces the water phase. Thus, the elastic network formed by the adsorbed hydrophobin remains intact, and even reinforced by the adjacent layer of globular protein. In contrast, the addition of the disordered protein β-casein leads to softening of the HFBII adsorption layer. Similar (an even stronger) effect is produced by the nonionic surfactant Tween 20. This can be explained with the penetration of the hydrophobic tails of β-casein and Tween 20 between the HFBII molecules at the interface, which breaks the integrity of the hydrophobin interfacial elastic network. The analyzed experimental data for the surface shear rheology of various protein adsorption layers comply with a viscoelastic thixotropic model, which allows one to determine E(sh) and η(sh) from the measured storage and loss moduli, G' and G″. The results could contribute for quantitative characterization and deeper understanding of the factors that control the surface rigidity of protein adsorption layers with potential application for the creation of stable foams and emulsions with fine bubbles or droplets.
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Affiliation(s)
- Krassimir D Danov
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria
| | - Peter A Kralchevsky
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria.
| | - Gergana M Radulova
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria
| | - Elka S Basheva
- Department of Chemical Engineering, Faculty of Chemistry and Pharmacy, Sofia University, 1164 Sofia, Bulgaria
| | - Simeon D Stoyanov
- Unilever Research & Development, 3133AT Vlaardingen, The Netherlands; Laboratory of Physical Chemistry and Colloid Science, Wageningen University, 6703HB Wageningen, The Netherlands
| | - Eddie G Pelan
- Unilever Research & Development, 3133AT Vlaardingen, The Netherlands
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Affiliation(s)
- Eric Dickinson
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, United Kingdom;
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Ruth DP, Gunton JD, Rickman JM, Li W. The impact of anisotropy and interaction range on the self-assembly of Janus ellipsoids. J Chem Phys 2014; 141:214903. [DOI: 10.1063/1.4902823] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- D. P. Ruth
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | - J. D. Gunton
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | - J. M. Rickman
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA
- Department of Materials Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | - Wei Li
- Materials Research Laboratory, UC Santa Barbara, Santa Barbara, California 93106, USA
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Angarska J, Ivanova D, Gerasimova A, Balashev K. Competitive adsorption of bovine serum albumin and n-dodecyl-β-d-maltoside in foam films. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2013.12.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Stanimirova RD, Marinova KG, Danov KD, Kralchevsky PA, Basheva ES, Stoyanov SD, Pelan EG. Competitive adsorption of the protein hydrophobin and an ionic surfactant: Parallel vs sequential adsorption and dilatational rheology. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Radulova GM, Danov KD, Kralchevsky PA, Petkov JT, Stoyanov SD. Shear rheology of hydrophobin adsorption layers at oil/water interfaces and data interpretation in terms of a viscoelastic thixotropic model. SOFT MATTER 2014; 10:5777-5786. [PMID: 24981289 DOI: 10.1039/c4sm00901k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Here, we investigate the surface shear rheology of class II HFBII hydrophobin layers at the oil/water interface. Experiments in two different dynamic regimes, at a fixed rate of strain and oscillations, have been carried out with a rotational rheometer. The rheological data obtained in both regimes comply with the same viscoelastic thixotropic model, which is used to determine the surface shear elasticity and viscosity, E(sh) and η(sh). Their values for HFBII at oil/water interfaces are somewhat lower than those at the air/water interface. Moreover, E(sh) and η(sh) depend on the nature of oil, being smaller for hexadecane in comparison with soybean-oil. It is remarkable that E(sh) is independent of the rate of strain in the whole investigated range of shear rates. For oil/water interfaces, E(sh) and η(sh) determined for HFBII layers are considerably greater than for other proteins, like lysozyme and β-casein. It is confirmed that the hydrophobin forms the most rigid surface layers among all investigated proteins not only for the air/water, but also for the oil/water interface. The wide applicability of the used viscoelastic thixotropic model is confirmed by analyzing data for adsorption layers at oil/water interfaces from lysozyme and β-casein - both native and cross-linked by enzyme, as well as for films from asphaltene. This model turns out to be a versatile tool for determining the surface shear elasticity and viscosity, E(sh) and η(sh), from experimental data for the surface storage and loss moduli, G' and G''.
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Affiliation(s)
- Gergana M Radulova
- Department of Chemical Engineering, Faculty of Chemistry & Pharmacy, Sofia University, 1164 Sofia, Bulgaria.
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Penfold J, Thomas RK, Li P, Petkov JT, Tucker I, Cox AR, Hedges N, Webster JRP, Skoda MWA. Impact of the degree of ethoxylation of the ethoxylated polysorbate nonionic surfactant on the surface self-assembly of hydrophobin-ethoxylated polysorbate surfactant mixtures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9741-9751. [PMID: 25046802 DOI: 10.1021/la5022627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Neutron reflectivity measurements have been used to study the surface adsorption of the polyethylene sorbitan monostearate surfactant, with degrees of ethoxylation varying from 3 to 20 ethylene oxide groups, with the globular protein hydrophobin. The surface interaction between the ethoxylated polysorbate nonionic surfactants and the hydrophobin results in self-assembly at the air-solution interface in the form of a well-defined layered surface structure. The surface interaction arises from a combination of the hydrophobic interaction between the surfactant alkyl chain and the hydrophobic patch on the surface of the hydrophobin, and the hydrophilic interaction between the ethoxylated sorbitan headgroup and the hydrophilic regions on the surface of the hydrophobin. The results presented show that varying the degree of ethoxylation of the polysorbate surfactant changes the interaction between the surfactant and the hydrophobin and the packing, and hence the evolution in the resulting surface structure. The optimal degree of ethoxylation for multilayer formation is over a broad range, from of order 6 to 17 ethylene oxide groups, and for degrees of ethoxylation of 3 and 20 only monolayer adsorption of either the surfactant or the hydrophobin is observed.
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Affiliation(s)
- Jeffrey Penfold
- Physical and Theoretical Chemistry Laboratory, Oxford University , South Parks Road, Oxford OX1 2JD, United Kingdom
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Hydrophobin film structure for HFBI and HFBII and mechanism for accelerated film formation. PLoS Comput Biol 2014; 10:e1003745. [PMID: 25079355 PMCID: PMC4117420 DOI: 10.1371/journal.pcbi.1003745] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 06/12/2014] [Indexed: 11/24/2022] Open
Abstract
Hydrophobins represent an important group of proteins from both a biological and nanotechnological standpoint. They are the means through which filamentous fungi affect their environment to promote growth, and their properties at interfaces have resulted in numerous applications. In our study we have combined protein docking, molecular dynamics simulation, and electron cryo-microscopy to gain atomistic level insight into the surface structure of films composed of two class II hydrophobins: HFBI and HFBII produced by Trichoderma reesei. Together our results suggest a unit cell composed of six proteins; however, our computational results suggest P6 symmetry, while our experimental results show P3 symmetry with a unit cell size of 56 Å. Our computational results indicate the possibility of an alternate ordering with a three protein unit cell with P3 symmetry and a smaller unit cell size, and we have used a Monte Carlo simulation of a spin model representing the hydrophobin film to show how this alternate metastable structure may play a role in increasing the rate of surface coverage by hydrophobin films, possibly indicating a mechanism of more general significance to both biology and nanotechnology. Filamentous fungi release a specific type of protein, belonging to a protein family known as “hydrophobins” into their environment to control interfaces in a fashion that promotes growth. Such protein coatings are the mechanism that allows for the mycelia to grow out of the water and into the air. When these hydrophobins form films at the air-water interface and on the surface of solid objects immersed in water, they impart properties to those surfaces that has led to their use in a wide range of industrial applications. Of particular interest is the properties they impart to air liquid interfaces, and as a mechanism to bring protective materials to coat nanoparticles in nanotechnology applications. A more detailed knowledge of the structure of these surfaces will allow for augmentation of their function that is possible through genetic engineering of the hydrophobins themselves. In this study we have combined computational and experimental methods to develop atomistic level insight into the structure of this surface for two important hydrophobins: HFBI and HFBII of Trichoderma reesei. In addition to insight into the surface structure, we have uncovered an intriguing possible new mechanism for film formation, which may explain some of the striking properties of hydrophobin films, and could be extended to a more general mechanism.
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